1. Field of the Invention
The present invention relates to attachments for front end loaders and more particularly to attachments used in ripping pavement or the surface of the ground.
2. Related Art
There are several types of ripping attachments in the present art for ripping pavement or any solid ground surface to allow further excavating or replacement. In general, prior art has several deficiencies, two of which center around the method in which the ripping is normally done.
First, most ripping attachments are mounted in conjunction with the bucket of the front end loader. This arrangement puts excessive strain on the bucket, using it for a task for which it was not designed. The bucket, while being capable of digging into ground, was not designed to rip into pavement or concrete.
Second, The ripping attachments are used in the forward direction. When the front end loader is being used in conjunction with a ripper attachment, operating it in the forward direction limits the duration for which it is used. In going forward while ripping, materials such as rocks and other debris accumulate in the bucket and must be emptied from time to time.
Some United States patents that are indicative of the state of the art are as follows.
U.S. Pat. No. 4,151,664, titled xe2x80x9cRipper Attachment for Backhoe or Front End Loaderxe2x80x9d, issued to Nicholas Maura, relates to an attachment which, for a backhoe bucket, includes a pair of connected rippers attached to the inside of the bucket and for a front end loader, at least three connected rippers attached inside the bucket. The rippers are attached by pins to the sides and upper bottom portion of the bucket. The earth engaging ends of the rippers are above the bucket edge so that the rippers will dislodge earth which subsequently falls into the bucket and the bucket edge can be used for the finish work without ripper interference.
U.S. Pat. No. 5,564,885, titled xe2x80x9cMultipurpose Work Attachment for a Front End Loaderxe2x80x9d, issued to Frank P. Staben, Jr., relates to a work attachment for a front end loader of the type having hydraulically actuated frame arms for supporting and manipulating a work attachment at the front of the vehicle. The work attachment includes a scoop or bucket in combination with a laterally extending row of ripper teeth mounted at the lower edge of the bucket and adapted for hydraulic actuation between an upper stored position and a downwardly extending deployed position for ripping earth upon vehicle movement in a reverse direction. The teeth are also used for retaining and locking and auxiliary attachment such as a fork lift unit onto the bucket. Additionally, an hydraulically actuated grapple hook can be mounted onto the bucket for use in combination with the bucket and fork lift unit.
The main problem with this device is that all the digging strain is put on the bucket and the hydraulics which actuate the ripper teeth. This arrangement was designed to work on the small skid-steer front end loaders marketed by Melroe Company under the trademark BOBCAT. Although it may be suitable these light duty front end loaders, its design is unsuitable for heavy equipment, such as that used in highway repair and construction.
The present invention provides a solution to the deficiencies of prior art in a method and apparatus for ripping solid ground or even pavement. As an apparatus, the present invention includes an attachment for a front end loader which includes a hollow tube mounted on a shaft between the arms of a front end loader directly behind the bucket of the loader. Closely machined bushings are welded and braced on the inside bottom surface of metal brackets fixed to the arms of the loader. These closely machined bushings are adapted to receive the shaft which is longer than the tube which covers it and extends out from the ends of the hollow tube. Ripper brackets are welded to the exterior surface of the hollow tube. Ripper teeth are mounted on the end of each bracket in a manner such that the pointed ends of the teeth are pointing towards the rear of the front end loader. Connecting rods are attached to both the exterior cylindrical surface of the hollow tube and the back surface of the loader bucket. When the bucket is tilted toward the operator, the hollow tube, through the operation of the connecting rods, rotates downward to a ripping position. Stops are welded on the metal brackets fixed to the arms of the front end loader and operate in cooperation with flanges mounted on the outer periphery of the ends of the hollow tube. When the bucket is tilted upward, the hollow tube rotates downward until the flanges come in contact with the stops. The bucket carrying the attachment having the ripping teeth, may be lowered to place the ripping teeth in contact with the ground. At this time the pointed ends of the ripping teeth are directed toward the ground and the back of the front end loader. The stops welded on the arms in cooperation with the flanges on the hollow tube receive the strain of a ripping operation.
To disengage, the bucket and ripping teeth may be raised by the front end loader arms. The bucket is then tilted to the level position. When the bucket is level the connecting rods force the hollow tube to rotate upward lifting the ripping teeth up and away from the ground surface.
To begin a ripping operation, the operator tilts the bucket upward, rotating the ripping teeth downward. The front end loader arms are lowered and the ripping teeth come in contact with the ground surface and can even be forced into the surface, whether solid ground or pavement. The operator then places the front end loader in reverse and backs up. Because of the configuration of the ripping teeth and the bucket, the operator may back up any distance required without having to stop and empty the bucket.
To cease a ripping operation, the operator stops the front end loader and lifts the arms. This lifts the bucket and ripping teeth. The operator tilts the bucket downward to a level position, which directs the points of the ripping teeth upward and away from the ground so that the operator may now perform smoothing or leveling work.
The present invention provides an apparatus for attachment to the arms of a front end loader having a front bucket that has machined bushings welded and braced on metal brackets fixed to the side of the front end loader arms. A hollow tube is mounted on a shaft between the arms with the shaft adapted to attach to the machined bushings. Ripper brackets are mounted to the outside of the hollow tube and ripping teeth are fixed to the end of each of the ripper brackets. Connecting rods are attached to the hollow tube and the bucket of the front end loader. The shaft is configured to extend from the ends of the hollow tube into the machined bushings. Stops are welded on the metal brackets on the arms of the front end loader to butt against welded members on the ends of the hollow tube when the bucket is tilted upward. These stops prevent contact between the riper brackets on the hollow tube and the bucket.
The present invention also provides a method for ripping a ground surface using a front end loader having a bucket that includes attaching a hollow tube having brackets with ripper teeth mounted thereon between the arms of the front end loader. The hollow tube is secured to the bucket so that the hollow tube moves in conjunction with the bucket. Stops are fixed to the arms of the front end loader to prevent contact between the brackets and the bucket. The bucket is tilted upward causing the ripper teeth to point downward and toward the back of the front end loader. The front end loader arms are lowered and the front end loader is backed up. To cease operation, the front end loader is stopped, the front end loader arms are lifted and the bucket is tilted downward to the level position causing the ripper teeth to point upward away from the ground surface.